The present invention generally pertains to injection molding of plastic products and is particularly directed to improvement in methods of controlling the wall thickness of a plastic product while being injection molded and improvement in methods of reducing the clamping force requirements of a plastic product while being injection molded.
Prior art methods for controlling the wall thickness of a plastic product while being injection molded and for reducing the clamping force requirements of a plastic product while being injection molded are described in U.S. Pat. No. 3,375,554 to Blumer, U.S. Pat. No. 3,737,272 to Segmuller, U.S. Pat. No. 3,995,007 to Spiegelberg, U.S. Pat. No. 4,264,295 to Hingley and U.S. Pat. Nos. 4,381,275; 4,467,994; 4,508,676 and 4,789,326 all to Sorensen.